Project Summary/Abstract The Food and Drug Administration, Center for Tobacco Products has articulated as one of its research priorities the identification of in vitro models and assays for assessing tobacco constituent or compound hazards and for comparing the respiratory toxicity of two different tobacco products. The Institute for In Vitro Science (IIVS), in Gaithersburg, MD is a non-profit organization devoted to the use of in vitro approaches to address the identification of chemical hazards. IIVS, with the advice of an expert steering committee, is organizing a Workshop, ?Assessment of In Vitro COPD Models for Tobacco Regulatory Science?. The Workshop will bring together the important stakeholders (academia, industry, regulatory scientists, and other interested parties) to have a focused discussion on the currently available cell culture COPD models that are potentially capable of assessing tobacco product-induced pulmonary toxicity. The Workshop will be held 8-10 December 2014 at the Bethesda North Marriott Hotel and Conference Center, North Bethesda, MD. The Workshop will include a number of oral presentations, time for formal discussion between participants and speakers, breakout group sessions to address specific questions in a small group format, a report-out of the breakout group conclusions, a poster session for detailed technical discussions and ample time during networking events and break periods for attendees to have informal discussions. The oral presentations will include: (1) Overview presentations from various stakeholders including: The FDA Center for Tobacco Products, the Tobacco Industry, the Animal Protection Organization, PETA; (2) Overview presentations to describe the clinical aspects of COPD, the etiology of COPD and general in vitro models that have been developed to understand the etiologies of COPD that may prove useful in evaluating the relative toxicity of various smoked tobacco products; and (3) Detailed presentations describing the features, technical aspects and effects that can be evaluated by specific in vitro models. The in vitro model presentations will be divided into four sessions (with 2-3 individual talks per session) that address the four major etiologies relevant to tobacco smoke induced COPD: (1) Inflammation and oxidative stress, (2) Ciliary dysfunction and ion transport, (3) Goblet Cell Hyperplasia and Mucus Production and (4) Parenchymal/bronchial tissue destruction and remodeling. The breakout session will allow small groups to discuss a series of questions concerning the technical aspects, relevance and utility of the various specific in vitro models to evaluate the comparative toxicity of different tobacco products. Based on workshop discussions, conclusions concerning the readiness of current models for regulatory application and approaches to improving models and developing new potentially better models will be drawn and published. The Workshop will be geared toward advancing science- based assessment and regulation of tobacco products with an ultimate goal of contributing to the public health effort to reduce the toxicity of tobacco products.